Taxonomic continuum of Alchemilla (Rosaceae) in Estonia

Abstract

23 widespread apomictic Alchemilla microspecies occurring in Estonia are analyzed to investigate whether the species and higher rank taxa are distinct, how variable these taxa are and which characters distinguish them better. Cluster analysis, discriminant analysis, analysis of variance, principal component analysis and continuum analysis are used for data processing. The characters form four correlative groups, describing (i) vegetative and (ii) generative parts of the plant body, (iii) hairiness characters and, (iv) leaf teeth measurements. The best characters according to analysis of variance for disünguishing species are hairiness characters, but often they distinguish only few species very clearly and cannot be used for the remaining ones. Hence the other characters cannot be excluded. From the studied species only A. plicata, A. semilunaris and A. lindbergiana are significantly distinct from all others. The remaining ones form a complicated network of mutually indistinct pairs. Higher rank taxa — sections and series according to Rothmaler, Fröhner and Yuzepchuk are better separated, containing very few mutually indistinct pairs. Results from species centroids' clustering are most congruent with Fröhner's system, but still some changes seem to be necessary and a corrected system is proposed here. Section Plicatae is split into two series: Pubescentes and Barbulatae, sections Alchemilla, Ultravulgares and Decumbentes are joined as three series of section Hirsutae, and A. filicaulis is moved from section Plicatae to section Coriaceae. Coriaceae should also be split into three series: Exuentes (A. filicaulis), Glabricaules (A. glabricaulis) and Coriaceae (other species).